/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.physics.box2d.joints;

import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Joint;
import com.badlogic.gdx.physics.box2d.World;

/**
 * The pulley joint is connected to two bodies and two fixed ground points. The pulley supports a ratio such that: length1 + ratio
 * * length2 <= constant Yes, the force transmitted is scaled by the ratio. The pulley also enforces a maximum length limit on
 * both sides. This is useful to prevent one side of the pulley hitting the top.
 */
public class PulleyJoint extends Joint {
	/*JNI
#include <Box2D/Box2D.h> 
	 */

    /**
     * Get the first ground anchor.
     */
    private final float[] tmp = new float[2];
    private final Vector2 groundAnchorA = new Vector2();
    /**
     * Get the second ground anchor.
     */
    private final Vector2 groundAnchorB = new Vector2();

    public PulleyJoint(World world, long addr) {
        super(world, addr);
    }

    public Vector2 getGroundAnchorA() {
        jniGetGroundAnchorA(addr, tmp);
        groundAnchorA.set(tmp[0], tmp[1]);
        return groundAnchorA;
    }

    private native void jniGetGroundAnchorA(long addr, float[] anchor); /*
		b2PulleyJoint* joint = (b2PulleyJoint*)addr;
		anchor[0] = joint->GetGroundAnchorA().x;
		anchor[1] = joint->GetGroundAnchorA().y;
	*/

    public Vector2 getGroundAnchorB() {
        jniGetGroundAnchorB(addr, tmp);
        groundAnchorB.set(tmp[0], tmp[1]);
        return groundAnchorB;
    }

    private native void jniGetGroundAnchorB(long addr, float[] anchor); /*
		b2PulleyJoint* joint = (b2PulleyJoint*)addr;
		anchor[0] = joint->GetGroundAnchorB().x;
		anchor[1] = joint->GetGroundAnchorB().y;
	*/

    /**
     * Get the current length of the segment attached to body1.
     */
    public float getLength1() {
        return jniGetLength1(addr);
    }

    private native float jniGetLength1(long addr); /*
		b2PulleyJoint* joint = (b2PulleyJoint*)addr;
		return joint->GetLengthA();
	*/

    /**
     * Get the current length of the segment attached to body2.
     */
    public float getLength2() {
        return jniGetLength2(addr);
    }

    private native float jniGetLength2(long addr); /*
		b2PulleyJoint* joint = (b2PulleyJoint*)addr;
		return joint->GetLengthB();
	*/

    /**
     * Get the pulley ratio.
     */
    public float getRatio() {
        return jniGetRatio(addr);
    }

    private native float jniGetRatio(long addr); /*
		b2PulleyJoint* joint = (b2PulleyJoint*)addr;
		return joint->GetRatio();
	*/
}
